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Session Beans

Stateless Session Beans

Figure B-6. Life-cycle state diagram of the stateless session bean

Figure B-7. Creation and removal of stateless session beans

Table B-2 summarizes the operations that are legal for a stateless session bean. The allowed operations are the same for both EJB 2.0 and 1.1, except for the SessionContext methods getEJBLocalHome() and getEJBLocalObject(), which are specific to EJB 2.0.

Table B-2. Allowed operations for stateless session beans

	Container-managed transactions	Bean-managed transactions
Method	Allowed operations
`ejbCreate()` `ejbRemove()`	`EntityContext` methods: `getEJBHome()` `getEJBLocalHome()` `getEJBObject()` `getEJBLocalObject()` JNDI ENC contexts: Properties: `java:comp/env`	`EntityContext` methods: `getEJBHome()` `getEJBLocalHome()` `getEJBObject()` `getEJBLocalObject()` `getUserTransaction()` JNDI ENC contexts: Properties: `java:comp/env`
Business methods	`EntityContext` methods: `getEJHome()` `getEJBLocalHome()` `getCallerPrincipal()` `isCallerInRole()` `getRollbackOnly()` `setRollbackOnly()` `getEJBObject()` `getEJBLocalObject()` JNDI ENC contexts: Properties: `java:comp/env` Resource managers: `java:comp/env/jdbc` EJB references: `java:comp/env/ejb`	`EntityContext` methods: `getEJHome()` `getEJBLocalHome()` `getCallerPrincipal()` `isCallerInRole()` `getEJBObject()` `getEJBLocalObject()` `getUserTransaction()` JNDI ENC contexts: Properties: `java:comp/env` Resource managers: `java:comp/env/jdbc` EJB references: `java:comp/env/ejb`
`ejbActivate()` `ejbPassivate()`	Not supported (stateless beans do not use these methods)	Not supported (stateless beans do not use these methods)

Stateful Session Beans

Figure B-8. Life-cycle state diagram of the stateful session bean

Figure B-9. Life cycle of a stateful session bean with the SessionSynchronization interface

Figure B-10. Creation and removal of stateful session beans

Figure B-11. Activation process of stateful session beans

Figure B-12. Transaction notification in SessionSynchronization session beans

Table B-3 summarizes the operations that are legal for a stateful session bean. The allowed operations are the same for both EJB 2.0 and 1.1, except for the SessionContext methods getEJBLocalHome() and getEJBLocalObject(), which are specific to EJB 2.0.

Table B-3. Allowed operations for stateful session beans

	Container-managed transactions	Bean-managed transactions
Method	Allowed operations
`setSessionContext()`	`EntityContext` methods: `getEJBHome()` `getEJBLocalHome()` JNDI ENC contexts: Properties: `java:comp/env`	`EntityContext` methods: `getEJBHome()` `getEJBLocalHome()` JNDI ENC contexts: Properties: `java:comp/env`
`ejbCreate()` `ejbRemove()` `ejbActivate()` `ejbPassivate()`	`EntityContext` methods: `getEJBHome()` `getEJBLocalHome()` `getCallerPrincipal()` `isCallerInRole()` `getEJBObject()` `getEJBLocalObject()` JNDI ENC contexts: Properties: `java:comp/env` Resource managers: `java:comp/env/jdbc` EJB references: `java:comp/env/ejb`	`EntityContext` methods: `getEJBHome()` `getEJBLocalHome()` `getCallerPrincipal()` `isCallerInRole()` `getEJBObject()` `getEJBLocalObject()` `getUserTransaction()` JNDI ENC contexts: Properties: `java:comp/ env` Resource managers: `java:comp/env/jdbc` EJB references: `java:comp/env/ejb`
Business methods	`EntityContext` methods: `getEJBHome()` `getEJBLocalHome()` `getCallerPrincipal()` `isCallerInRole()` `getRollbackOnly()` `setRollbackOnly()` `getEJBObject()` `getEJBLocalObject()` JNDI ENC contexts: Properties: `java:comp/env` Resource managers: `java:comp/env/jdbc` EJB references: `java:comp/env/ejb`	`EntityContext` methods: `getEJHome()` `getEJBLocalHome()` `getCallerPrincipal()` `isCallerInRole()` `getEJBObject()` `getEJBLocalObject()` `getUserTransaction()` JNDI ENC contexts: Properties: `java:comp/env` Resource managers: `java:comp/env/jdbc` EJB references: `java:comp/env/ejb`
`afterBegin()` `beforeCompetion()`	`EntityContext` methods: `getEJBHome()` `getEJBLocalHome()` `getCallerPrincipal()` `isCallerInRole()` `getRollbackOnly()` `setRollbackOnly()` `getEJBObject()` `getEJBLocalObject()` JNDI ENC contexts: Properties: `java:comp/env` Resource managers: `java:comp/env/jdbc` EJB references: `java:comp/env/ejb`	Not supported (bean-managed transaction beans cannot implement the `SessionSynchronization` interface)
`afterCompletion()`	`EntityContext` methods: `getEJBHome()` `getEJBLocalHome()` `getCallerPrincipal()` `isCallerInRole()` `getEJBObject()` `getEJBLocalObject()` JNDI ENC contexts: Properties: `java:comp/env`	Not supported (bean-managed transaction beans cannot implement the `SessionSynchronization` interface)

Message-Driven Beans

Figure B-13. Message-driven bean life-cycle state diagram

Figure B-14. Message-driven bean sequence diagram

Interactions Between Exceptions and Transactions

Table B-4 summarizes what happens to a transaction if an exception is thrown while the transaction is in process.

Table B-4. Exception summary for session and entity beans

Transaction scope	Transaction type attributes	Exception thrown	Container’s action	Client’s view
Client-initiated transaction. The transaction is started by the client (application or EJB) and is propagated to the enterprise bean method.	transaction-type = Container transaction-attribute = `Required` \| `Mandatory` \| `Supports`	Application exception	If the EJB invoked `setRollbackOnly()`, mark the client’s transaction for rollback. Rethrow the application exception.	Receives the application exception. The client’s transaction may or may not have been marked for rollback.
		System exception	Mark the client’s transaction for rollback. Log the error. Discard the instance. Rethrow the JTA `TransactionRolledbackException` to remote clients or the `javax.ejb.TransactionRolledbackLocalException` to EJB 2.0 local clients.	Remote clients receive the JTA `TransactionRolledbackException`; local clients receive the `javax.ejb.TransactionRolledbackLocalException`. The client’s transaction has been rolled back.
Container-initiatedtransaction. The transaction started when the EJB’s method was invoked and will end when the method completes.	transaction-type = Container transaction-attribute = `Required` \| `RequiresNew`	Application exception	If the EJB invoked `setRollbackOnly()`, roll back the transaction and rethrow the application exception. If the EJB did not explicitly roll back the transaction, attempt to commit the transaction and rethrow the application exception.	Receives the application exception. The EJB’s transaction may or may not have been rolled back. The client’s transaction is not affected.
		System exception	Roll back the transaction. Log the error. Discard the instance. Rethrow the `RemoteException` to remote clients or the `EJBException` to EJB 2.0 local clients.	Remote clients receive the `RemoteException`; local EJB 2.0 clients receive the `EJBException`. The EJB’s transaction was rolled back. The client’s transaction may or may not be marked for rollback, depending on the vendor.
The bean is not part of a transaction. The EJB was invoked but does not propagate the client’s transaction and does not start its own transaction.	transaction-type = Container transaction-attribute = `Never` \| `NotSupported` \| `Supports` \|	Application exception	Rethrow the application exception.	Receives the application exception. The client’s transaction is not affected.
		System exception	Log the error. Discard the instance. Rethrow the `RemoteException` to remote clients or the `EJBException` to EJB 2.0 local clients.	Remote clients receive the `RemoteException`; local EJB 2.0 clients receive the `EJBException`. The client’s transaction may or may not be marked for rollback, depending on the vendor.
Bean-managed transaction. The stateful or stateless session EJB uses the `EJBContext` to explicitly manage its own transaction.	transaction-type = Bean transaction-attribute = Bean-managed transaction EJBs do not use transaction attributes.	Application exception	Rethrow the application exception.	Receives the application exception. The client’s transaction is not affected.
		System exception	Roll back the transaction. Log the error. Discard the instance. Rethrow the `RemoteException` to remote clients or the `EJBException` to EJB 2.0 local clients.	Remote clients receive the `RemoteException`; local EJB 2.0 clients receive the `EJBException`. The client’s transaction is not affected.

Table B-5 summarizes the interactions between different types of exceptions and transactions in message-driven beans.

Table B-5. Exception summary for message-driven beans

Transaction scope	Transaction type attributes	Exception thrown	Container’s action
Container-initiated transaction. The transaction started before the `onMessage()` method was invoked and will end when the method completes.	transaction-type = Container transaction-attribute = `Required`	System exception	Roll back the transaction. Log the error. Discard the instance.
Container-initiated transaction. No transaction was started.	transaction-type = Container transaction-attribute = `NotSupported`	System exception	Log the error. Discard the instance.
Bean-managed transaction. The message-driven bean uses the `EJBContext` to explicitly manage its own transaction.	transaction-type = Bean transaction-attribute = Bean-managed transaction EJBs do not use transaction attributes.	System exception	Roll back the transaction. Log the error. Discard the instance.

Transaction scope

Transaction type attributes

Exception thrown

Container’s action

Container-initiated transaction.

The transaction started before the onMessage() method was invoked and will end when the method completes.

transaction-type =

Container

transaction-attribute =

Required

System exception

Roll back the transaction.

Log the error.

Discard the instance.

Container-initiated transaction.

No transaction was started.

transaction-type =

Container

transaction-attribute =

NotSupported

System exception

Log the error.

Discard the instance.

Bean-managed transaction.

The message-driven bean uses the EJBContext to explicitly manage its own transaction.

transaction-type =

Bean

transaction-attribute =

Bean-managed transaction EJBs do not use transaction attributes.

System exception

Roll back the transaction.

Log the error.

Discard the instance.

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Table of Contents for Session Beans

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Session Beans

Stateless Session Beans

Stateful Session Beans

Message-Driven Beans

Interactions Between Exceptions and Transactions

Table of Contents for
Session Beans